Add Mysql ANTLR4 parser

[NQPhuc]

Summary

• Add new mysql parser using antlr grammar (based on: https://github.com/antlr/grammars-v4/tree/master/sql/mysql/Positive-Technologies)

• The old postgres parser can still be used through: sql2dbml --mysql-legacy

• Implement MySQLASTGen visitor to generate the AST from the parse tree. Note that not all nodes will be visited in our visitor, only the nodes related to model_structure and thus DBML is.

• Update tests and doc.

• Improve Error Handling for both Postgres and Mysql new parser to be able to throw multiple errors.

• Note: Files in ANTLR/parsers/mysql are auto-generated and can be safely ignored.

• Benchmark result
  

Issue

• Syntax Error: "Expected ")" or fields but "`" found." for "GENERATED ALWAYS AS" #482
• MySQL syntax error for start transaction #465
• [mysql] sql2dbml cannot correctly parse simple mysql dumps #304
• [mysql] FULLTEXT KEY is not supported in sql2dbml #303
• [question] can i use mysql binary option? #216
• sql2dbml cannot parse MySQL row format #120

Lasting Changes (Technical)

• Update AST classes typing.
• Unify commonly used constants in both MySQLASTGen and PostgresASTGen.
• Update eslint ecmaVersion to 2020 to recognize new syntax such as ?.

Checklist

Please check directly on the box once each of these are done

• Documentation (if necessary)
• Tests (integration test/unit test)
• Integration Tests Passed
• Code Review